AmM°ayr;il>93arin"}  Gleanings  from  the  German  Journals.  zzi 
potassium  iodide  solution  for  hypodermic  injections.  F.  Riederer 
always  noticed  a  dark  gray  residue  when  making  up  the  solution; 
this  residue,  amounting  to  about  0-5  per  cent.,  was  found  to  consist 
largely  of  metallic  mercury,  while  the  solution  contained  some  red 
iodide  of  mercury.  From  this  it  is  evident  that  potassium  iodide 
solution  cannot  be  used  for  the  dissolving  of  the  mercurial  salt  with- 
out decomposition. — Pharm.  Ztsch.  f.  Russl.,  1893,  101. 
The  use  of  crude  carbolic  acid  and  wood-tar,  for  disinfecting  pur- 
poses, is  rather  wasteful  because  of  their  insolubility  in  water.  E. 
Hirschsohn,  in  a  series  of  experiments,  found  that  if  100  parts  of 
so-called  100  per  cent,  crude  carbolic  acid  was  agitated  with  50 
parts  moderately  finely  powdered  rosin  and  6-8  parts  sodium 
hydrate  dissolved  in  12-16  parts  of  water  until  solution  resulted, 
a  liquid  was  obtained  giving  an  almost  clear  solution  with  ten  vol- 
umes of  water.  The  solution  resembles  "  Lysol,"  differing  from  it, 
however,  in  not  being  miscible  with  petroleum-ether,  and  in  not 
producing  the  gelatinous  mass  upon  addition  of  two  or  three  vol- 
umes of  water.  Experiments  with  so-called  50  per  cent,  crude 
carbolic  acid  did  not  give  a  preparation  dissolving  perfectly  in  water  ; 
using  the  same  proportions  as  above,  the  preparation  resembled 
"creolin,"  giving  with  water  an  emulsion. 
In  experimenting  with  wood-tar  it  was  found  that  the  same  form- 
ula would  not  give  satisfactory  preparations  with  the  different  kinds 
of  tar.  While  in  the  case  of  birch-tar  the  above  proportions  proved 
satisfactory,  fir-tar  required  an  entirely  different  formula.  The  best 
results  were  obtained  by  using  100  parts  of  fir-tar,  10  parts  rosin 
and  6-7-5  parts  sodium  hydrate,  dissolved  in  12-15  parts  ol 
water.  These  preparations  do  not  give  entirely  clear  dilutions  with 
water,  but  upon  prolonged  standing  neither  an  oily  nor  tarry  layer 
separates. 
While  heat  is  not  essential  for  success  it  facilitates  the  solution 
of  the  rosin  in  the  carbolic  acid  and  tar  ;  the  sodium  hydrate,  how- 
ever, must  be  dissolved  in  the  specified  quantities  of  water  or 
inferior  preparations  will  result.  Attention  is  called  to  the  fact  that 
crude  carbolic  acid  is  met  with  which  will  give  good  preparations 
with  less  rosin  and  sodium  hydrate.  Other  oils,  like  oil  of  turpen- 
tine and  oil  of  eucalyptus,  can  be  made  miscible  by  following  the 
above  directions. — Pharm.  Ztschr.  f.  Russl.,  1893,  Nos.  8  and  9. 
Caffeine  salts. — By  direct  combination  with  the  acids,  and  drying 
